Brown azo dyestuffs.



UNITED STATES PATEN onnron.

KARL SCHIRMACHER AND HEINRICH ELVERT, OF HGCHST-ON-THE-MAIN, GERMANY, ASSIGNORS TQ FARBWERKE VORM. MEISTER LUCIUS & BRU'NING, OF HClCI-IST-OIW- THE-MAIN, GERMANY, A CORPORATION OF GERMANY,

BROWN .AZO DYESTUFFSQ No Drawing.

Y Specification of Ietters Patent. Application filed January 2, 1913. Serial N 0. 739,882.

Patented Nov. 4, 1913.

. fication.

lV e have found that valuable brown azo dyestuffs are obtained by combining a diazo compound of a p-amin0diaryl-sulfoxid with naphthalene-2-arylamino-S-oxy-G-sulfonic acid, The dyestuffs thus produced are brown powders, soluble in water to a brown solution, almost insoluble in ether, benzene and alcohol, and which dye wool brown tints of excellent fastness to washing. The constitution of said dyestuffs corresponds to the formula:

. I I aryF-SO-aryW-N-N-K\NH-aryl wherein aryl aryl and aryl mean aromatic residues and X means a sulfo .group.

By treating these dyestuffs with tin and hydrochloric acid they may, in the first instance,- be split up into naphthalene-Q-arylamino-T-amino-S-oxy-G-sulfonic acid and into p-amiuodiarylsulfoxids, the latter being eventually further reduced to paraa mino-diaryl-sulfids.

The following example illustrates the invention, the parts being by'weight: 22.9 parts of tol-yl-para amiuoplienylsulfoxid, obtained by condensing para-toluenesulfonic acid with anilin, are diazotized with parts of hydrochloric acid of 20 Be. specific gravity and 7 parts of sodium nitrite, and the (liazo solution. after it has been filtered.

15 introduced, while stirring. into a solution of 35 parts of uaphthaleuc-9phenyl-an1ino- S-oxy-G-sulfonic acid and T0 parts of calcined sodium carbonate. After the mixture has been stirred for several hours it is heated to 5040 0., whereupon a small quantity of common salt is added and the coloring matter separated by filtration. The dyestuff thus obtained has the formula 1 GH -CgEh-SO-C l-I -N=N ,-NH-C.H.

It forms, when dry, a deep-brownishblack powder, dissolving in concentrated sulfuric acid to a red solution. It dissolves to a brown solution in hot water. wherein it is more readily soluble than in cold water. and dyes wool fast brown tints.

aving now described our what .we claim is: r

1. As new products, the azo-dyestutl's of the constitution:

invention.

being a brown powder, soluble in water to a brown solution, almost insoluble in ether, benzeneand alcohol, and dyeingwool fast brown tlnts.

NaCwS-b tures in presence of two witnesses.

KARL SCHIRMACHER.

HEINRICH ELVERT. Witnesses:

JEAN GRUND, CARL GRUND.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Yatcnts, Washington, D. G.

In testimony whereof, we aflix our signa- 

